Numerical Simulation of Flow Field in Air Leakage Test Furnace

• Main Authors: Chih-ChiehKu, 古智杰
• Other Authors: S.Y. Lin
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/82696825836115735130

碩士 === 國立成功大學 === 航空太空工程學系 === 102 === The goal of paper uses ANSYS CFX to investigate the fluid fields in air leakage test furnace. We investigate the relationship among temperature trends and the turbine rotational speed, electric heating pipe temperature. In the simulation, we use high resolution scheme and K-Epsilon turbulence model to solve the incompressible Navier-Stokes equations. The mixed grid system which combines Hexahedral and prism meshes is used. First, several test problems, 3-D cavity flow; natural convection; and air leakage test for a plate with a hole, are simulated to understand the capability of the commercial program about the air leakage test. The numerical results are compared well with the experimental data performed by NCKU Fire Safety Research Center. Finally, the flow field and temperature in the furnace are investigated in detailed. We find out that the design angle and rotation speed of wind turbine are very important parameter to elevate temperature in the furnace. INTRODUCTION Fires often cause casualties due to smoke and heat. Heat is the most frightening factors. How to effectively control the proliferation of fire and smoke is very important issue. Fire doors are used to prevent the spread of smoke within a certain time. Basically a fire door testing may spend hundreds of thousands. Using ANSYS CFX can predict the performance of door and save. The goal of paper is to simulate the fluid field in air leakage test furnace by using ANSYS CFX. We investigate the temperature trends by changing the turbine rotational speed and electric heating pipe temperature. RESULTS AND DISCUSSION In the simulation, we use high resolution scheme and K-Epsilon turbulence model to solve the incompressible Navier-Stokes equations. The mixed grid system which combines Hexahedral and prism meshes is used. First, several test problems, 3-D cavity flow; natural convection; and air leakage test for a plate with a hole, are simulated to understand the capability of the commercial program. About the air leakage test, the numerical results are compared well with the experimental data performed by NCKU Fire Safety Research Center. Finally, the flow field and temperature distribution in the furnace are investigated in detailed. CONCLUSION The gas flow is roughly trend by buoyancy and wind turbine design. Heat will accumulate at the right part and are mainly affected by the wind turbine position. We find out that the design angle and rotation speed of wind turbine are very important parameter to elevate temperature in the furnace. In the furnace, temperature trends by wind turbine and heating pipes. Some lower temperature gas was caused by the door and the gas flowing through the electro-thermal tube. The air flow speed is so fast that heating electro-thermal tube can not effectively heating.